78 REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 
larger proportion of pines; and in some parts of the Coosa Valley, in 
Alabama, they are occasionally timbered with long-leaf pines and black- 
jack oaks almost exclusively. 
In the Valley of the Tennessee, in North Alabama, and around the 
margin of the limestone basin of Middle Tennessee, the cherty Subcar- 
boniferous limestones lie nearly horizontal, and they thus come to be 
the substratum of wide areas, which in these States are known as "bar- 
rens," from the comparative infertility of the soil, as compared with that 
of the adjoining limestone lands. These barren soils are usually thin 
and deficient in lime, and have a high percentage of siliceous matter. 
The timber consists of oaks, often shrubby and stunted, small hick- 
ories, dogwood, &c, in the lower latitudes, mixed with short-leaf pines. 
The oaks are of several species, but the post oak and black-jack appear 
to be the most common. 
These lands are very sparingly cultivated in cotton, and hence need 
no special mention beyond what has been given. 
In their topography, the barrens are in contrast to the red loam lands 
which are adjacent to them. The hard, flinty, indestructible chert is 
worn into rough, precipitous hills wherever the somewhat level water- 
sheds break off towards the streams. 
West of the Mississippi, the same formations produce similar soils and 
topography in northern Arkansas, where the cherty ridges are clothed 
chiefly with mock ernut hickory and post and black-jack oaks. With these 
are associated, in those localities where the soil is more sandy, the yel- 
low or short-leaf pine (P. tceda). Along the declivities appear the white, 
red, and black oaks. Upon these formations in northern Arkansas also 
occur prairies of limited extent, surrounded with a growth of small trees. 
These prairies, which are not always of flat surface, are found along the 
gentle slopes or in the coves between the ridges. 
The bottom lands derived from these cherty limestones are generally 
highly productive. 
b. Sandstone soils. — The other class of siliceous soils is derived from 
the sandstones and grits of the Coal-measures. In general they are of 
only medium fertility, and are of comparatively little importance in the 
cultivation of cotton. Lately, however, in some of the eastern Cotton 
States, it has been found that with the use of commercial fertilizers 
very fair cotton crops may be produced upon these soils, which have in 
general a subsoil of yellowish loam, which is moderately impervious and 
holds well the fertilizers that may be applied to the land. 
In Alabama and East Tennessee a large area is underlaid by the Coal- 
measures, and the table lands or plateaus of a part of this area are ad- 
mirably situated and will doubtless some day be more generally culti- 
vated than is now the case. 
The best of these soils are light-colored loams, with yellowish or red- 
dish subsoils. These are capable of improvement and successful cult- 
ure. The gray soils with light-colored to whitish subsoils, deficient in 
